1. Field of the Invention
The present invention relates to an ink-jet head provided in a printer or the like, and particularly to an ink-jet head including a discharge element group in which plural discharge elements for discharging ink are disposed.
2. Description of the Related Art
An ink-jet head used for a printer, a facsimile or the like is formed of plural thin plates which are bonded with adhesive and are laminated. Through holes are provided in each of the thin plates, and by the through holes, a discharge element group is formed in which plural discharge elements having ink flow paths are disposed.
Each of the discharge elements includes a nozzle for discharging ink, and a pressure chamber communicates with the nozzle. A manifold for supplying ink is provided to communicate with the pressure chamber. An aperture for restricting the flow amount of ink is formed between the manifold and the pressure chamber. An actuator such as a piezoelectric element is fixed to the pressure chamber, and ink is pressurized and is sent from the pressure chamber by driving of the actuator. By this, a predetermined amount of ink is discharged from each nozzle.
According to the ink-jet head having the above structure, when the respective layers are bonded to each other, adhesive applied to the periphery of the discharge element group flows into the ink flow path of the discharge element disposed at the outer periphery of the discharge element group. Thus, there has been a problem that the ink flow path is blocked by the adhesive, and the discharge accuracy of the ink-jet head is lowered.
Japanese Patent Application No. 2002-280581 discloses an ink-jet head in which an opening part is provided around a pressure chamber. By this, adhesive applied to the periphery of a discharge element group flows into the opening part, and it is possible to prevent the pressure chamber from being blocked.
However, in the ink-jet head disclosed in Japanese Patent Application No. 2002-280581, when the amount of adhesive pushed out from the outside of the discharge element group toward the inside by lamination becomes large, there has been a fear that the adhesive overpasses the opening part and flows into the through hole forming the pressure chamber.
Besides, even if the flow of the adhesive into the pressure chamber is prevented, there has also been a problem that the adhesive flows into a through hole of another layer forming the ink flow path and the ink flow path is blocked. Especially, since an aperture for narrowing a flow path is required to be formed such that its cross-sectional area is small, an aperture plate itself forming the aperture is thin, and the volume of an opening part formed therein must be small. Thus, in the aperture of the discharge element disposed at the outer periphery of the discharge element group, even if the opening part is provided therearound, the adhesive is apt to flow in.